Know how to distinguish between products that offer real health benefits and others whose benefits have been invented for marketing purposes?

The shelves of organic supermarkets are increasingly stacked with "superfoods", but how are we to distinguish between products that offer real health benefits and others whose benefits have been invented for marketing purposes? We asked nutri-therapy specialist Olivia Charlet, who is also a marathon runner and naturopath, to separate fact from fiction.

Plants, seaweed and seeds: according to Olivia Charlet, these foods have specific health benefits because they contain nutrients that most people lack.

They may also be eaten to counterbalance the acidifying effects of an unhealthy diet heavy on meat, dairy products and refined sugar. As a rule, they should be taken in powdered form so that they can be digested easier.

Raw cacao to stock up on magnesium

With a magnesium content that is even higher than dark chocolate and without the sugar, raw cacao may be sold in its original bean form or packaged as a spread or powder. If you're not used to the taste, Charlet recommends starting with products that contain a percentage of cacao sugar, or raw cacao bars, which are less bitter than cacao beans. Two squares of a cacao bar can make a pleasant alternative to a more conventional dessert.

Chia seeds for omega-3s

Boost your intake of omega-3 fatty acids with chia seeds, an excellent breakfast food that's even more nutritious than linseed -- try adding two dessert spoonfuls to cereal. Chia seeds are composed of 48 percent omega-3, 20 percent protein and a high proportion of calcium. Filling and good for digestion, chia seeds combine well with vanilla, cinnamon, cacao, sugar and soy and almond milk in desserts.

Spirulina for chlorophyll

A freshwater algae popular with athletes who appreciate its 70 percent protein content, spirulina is, according to Charlet, an excellent remedy for digestive aliments. Along with vitamins, minerals and protein, spirulina has very high levels of chlorophyll, which helps to clean the alimentary canal and eliminate heavy metals.

Charlet suggests taking it in the form of powder or flakes mixed with hazelnut oil and avocado or banana. Another, more expensive algae, Klamath, contains less iron than spirulina, but is prized for its blue pigment, phycocyanin, which Charlet recommends as a tonic for auto-immune conditions.

Seaweed for iodine

Seaweed is an excellent source of iodine, essential for thyroid function. Ready-to-eat marinated mixes containing varieties like dulse, nori, wakamé and ulva lactuca are available from health food stores.

Maca for energy

A root vegetable and medicinal herb native to the high Andes, maca is prized for its usefulness in combating fatigue. A spoonful in the morning instead of your coffee can boost your energy for the rest of the day.

Sprouts for vitamins

An excellent addition to salads, sprouts like leek, lentil, chickpea and alfalfa sprouts are rich in protein, essential fatty acids, and amino acids. Sprouted seeds offer even more vitamins and enzymes.